Needing some advice on my relationship with my mom. Interested to see view from both parents and my age?

My parents got divorced when I was in 6th grade. It took till fall of my senior year in high school for it to be completely finalized. Throughout the divorce, I always agreed with my mother, whom I was extremely close with, even if it was lies. I only wanted to live her and would do anything to make that happen. As I learned more about the divorce (after I was 18 and out of court involvement) I learned that my mom would sneak around, lie to almost everyone, back out of responsibility whenever possible, and would lie so she wouldnt have to have visitation time with my brother and I. Its been two and a half years since she and I have talked. My brother (17) still has a year of visitation. He told me that she has changed and is a different person from what I knew her as. However, he has tried to talk to her/visit her and she is still doing everything to not have to visit or talk to him. I would love to believe my brother and would give anything to have some relationship with my mom again but idk if i can or if its even a good idea. I also know that it would break my dads heart to see me hurt by my mom again. I dont want to stir up trouble by "going back" i guess and attempting to talk to her but at the same time, she is my mom. Yeah she may have done a lot of hurtful things to my family and I but she will always be my mom and i will always miss her/want her back. I struggle with this decision because I dont want to hurt my family as well as mess up anything good in my own personal life by communicating with her, but at the same time i would love to be able to talk to her again. Help please?